SAN FRANCISCO: Atomic PR worked with Huntsworth to open a sister agency in February, a month before the London-based holding company acquired Atomic for $13.3 million.

H3O, which also focuses on analytics, digital, and social media, is led by Atomic veteran Rebecca West.

It has brought in clients like McAfee and TravelSort, according to Andy Getsey, who cofounded Atomic with James Hannon in 1999.

As part of the deal, Huntsworth acquired Atomic, H3O, and ComContext, its Web-based data analytics application. The ...